Cognitive behavioral panic control treatment (PCT) is a prescriptive, targeted psychotherapy, aimed at decreasing fear of bodily sensations, thought to be the pathogenic mechanism in Panic Disorder. PCT includes breathing retraining, cognitive reframing and interoceptive exposure. Studies confirm PCT superiority over wait list controls, however specificity of this treatment is not well established. Similarly, adequate data is not yet available to confirm the mediating role of the hypothesized mechanism of PCT's effectiveness - decrease in fear of bodily sensations. We undertook our previous study to investigate the question of specificity of a cognitive behavioral treatment, very similar to PCT, by comparing it to a control psychotherapy consisting of psychoeducation and reflective listening, now called Nonprescriptive Treatment (NPT). We found no significant differences between the cognitive behavioral treatment and NPT on any of the outcome measures. The objective of this renewal application is to investigate further the effectiveness of NPT. Since our initial study did not establish efficacy of NPT, but only found equivalence to PCT, we now propose to compare NPT to a placebo(PLA) treatment. We will also replicate the comparison of PCT and NPT. A further aim of the proposed study is to conduct analyses to explore mediation and moderation of treatment response. Novel data analytic strategies will be used to explore whether fear of bodily sensations appears to function as a mediator of outcome, and whether scores on ratings of the personality characteristic of reactance (fear of loss of interpersonal control) are differentially correlated with outcome of PCT and NPT. Since we will conduct this study in conjunction with the ongoing Multicenter Panic Disorder Treatment Study, we are requesting funding here only for the NPT cell. PLA and PCT cells will come from the Multicenter Study.